为什么在Javascript中.length后没有()? [英] Why no () after .length in Javascript?

问题描述

我是一名业余程序员，我学习过多种语言，几乎总是发现'length'是一种方法/功能.据我所知，我已经受过训练，任何方法调用之后都必须带括号，即使没有参数也是如此.

I'm a hobby programmer, I've studied several languages and almost always find that 'length' is a method/function. I've been trained, from what I can tell, that any method call must be called with a parenthesis after, even with no arguments.

在Javascript中不是....为什么?

Not so in Javascript.... Why?

C#.length()ROR .lenth()

C# .length() ROR .lenth()

等...

推荐答案

在Javascript中，它是属性，而不是函数.

In Javascript it's a property, not a function.

在像C这样的语言中，长度函数必须在整个字符串中循环才能找到结尾，因此将其作为一个函数是合乎逻辑的(因为它可以完成一些工作).在长度被保留为单独值的语言中，将其改为属性是合乎逻辑的(因为它只读取一个已经存在的值).

In languages like C where the length function has to loop through the entire string to find the end, it's logical to have it as a function (as it does some work). In languages where the length is kept as a separate value, it's logical to have it as a property instead (as it only reads an already existing value).

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